Concept

Échappement (horlogerie)

Publications associées (32)

Shaking force balancing of a 2-DOF isotropic horological oscillator

Simon Nessim Henein, Hubert Pierre-Marie Benoît Schneegans, Etienne Frédéric Gabriel Thalmann

Despite centuries of research and significant advances, the escapement mechanism used to count and maintain oscillations of mechanical time bases remains a complex mechanism and a major source of energy losses. We showed in previous work that, instead of t ...

2021

The Role of Geometrical Parameters in the Lubrication of the Swiss Lever Escapement

Stefano Mischler

The lubrication regimes of a contact pair escapement-ruby pallet of a Swiss lever escapement have been investigated combining the theory of fluid lubrication with a well-established kinematic and inverse dynamic multibody model. The kinematic analytical re ...

2021

Rocker oscillator time bases

Simon Nessim Henein, Ilan Vardi

Since the invention of the pendulum clock by Christiaan Huygens in 1657, precision timekeepers have been regulated by oscillators. Although the pendulum is not an isochronous oscillator, its introduction as a time basis for clock regulation led to a signif ...

2021

Control-Free Mechanical Oscillator Powered by Shape Memory Alloys

Yves Perriard, Paolo Germano, Thomas Guillaume Martinez, Sean Thomas

Shape Memory Alloy (SMA) based actuators have been commonly used in applications that require being compact and lightweight. In this paper, the inherent stiffness of a flexure-based linear guide is used to create a bias-spring SMA actuator which further re ...

IEEE2021

Tribological Approach to the Watch Movements

Valentine Agnès Madeleine Magnin

Mechanical watches are complex and sensitive systems that have to maintain a faultless precision over their lifetime. However, this precision can be altered by disturbances occurring during the functioning time, such as friction, lubricant drying, or wear, ...

EPFL2020

Force Reduction in a Short-Stroke Vibration Tubular Generator for Vehicle Energy Harvesting Application

Minh Trung Duöng

This paper examines methods to reduce the detent force and electromagnetic force in a short-stroke vibration tubular generator used to harvest energy from a vehicle suspension system but still achieve the design targets of power and power density. A well-k ...

2020

Design of a Flexure Based Low Frequency Foucault Pendulum

Simon Nessim Henein, Ilan Vardi, Patrick Robert Flückiger

The Foucault pendulum is a well-known mechanism used to demonstrate the rotation of the Earth. It consists in a pendulum launched on linear orbits and, following Mach’s Principle, this line of oscillation will remain fixed with respect to absolute space bu ...

2020

Flexure Pivot Oscillator With Intrinsically Tuned Isochronism

Simon Nessim Henein, Ilan Vardi, Etienne Frédéric Gabriel Thalmann, Mohammad Hussein Kahrobaiyan

The most important property for accurate mechanical time bases is isochronism: the independence of period from oscillation amplitude. This paper develops a new concept in isochronism adjustment for flexure-based watch oscillators. Flexure pivot oscillators ...

2020

Flexure Pivot Oscillators for Mechanical Watches

Etienne Frédéric Gabriel Thalmann

It appears that the concerted efforts of the watchmaking industry are leading towards a limit in mechanical watch accuracy. The general consensus in horology is that the time base's quality factor, a dimensionless number that characterizes the oscillator d ...

EPFL2020

Automatically Starting and Secured Detent Escapement for a Timepiece

Simon Nessim Henein, Ilan Vardi

A horological detent escapement for a horological movement arranged to transmit a torque from said horological movement to an oscillating regulating organ of said horological movement, the regulating organ comprising a first mobile body and the escapement ...

2019

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